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Growth of Large Single Crystals of Mgo

Description: The progressive identification of new high-technology applications and requirements for MgO single crystals in the commercial realm, as well as in DOE and other government-agency project areas, has resulted in an increased demand and international market for this material. Specifically, the demand for MgO crystals in large sizes and quantities is presently increasing due to existing and developing applications that include: (a) MgO substrates for the formation of electro-optic thin films and de… more
Date: June 12, 1997
Creator: Boatner, L. A. & Urbanik, M.
Partner: UNT Libraries Government Documents Department
open access

The effect of gettering on areal inhomogeneities in large-area multicrystalline-silicon solar cells

Description: Multicrystalline-silicon (mc-Si) materials and cells feature large areal variations in material and junction quality. The regions with poor device quality have been predicted to have more recombination current at forward bias than a simple area-weighted average due to the parallel interconnection of the good and bad regions by the front junction. The authors have examined the effect of gettering on areal inhomogeneities in large-area mc-Si cells. Cells with large areal inhomogeneities were foun… more
Date: October 1, 1997
Creator: Gee, J. M. & Sopori, B. L.
Partner: UNT Libraries Government Documents Department
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Microstructure of GaN Grown on (111) Si by MOCVD

Description: Gallium nitride was grown on (111) Si by MOCVD by depositing an AIN buffer at 108O"C and then GaN at 1060 {degrees}C. The 2.2pm layer cracked along {1-100} planes upon cooling to room temperature, but remained adherent. We were able to examine the microstructure of material between cracks with TEM. The character and arrangement of dislocation are much like those of GaN grown on Al{sub 2}O{sub 3}: -2/3 pure edge and - 1/3 mixed (edge + screw), arranged in boundaries around domains of GaN that ar… more
Date: December 17, 1998
Creator: Fleming, J.G.; Follstaedt, D.M.; Han, J. & Provencio, P.
Partner: UNT Libraries Government Documents Department
open access

Pulling of 3 mm diameter AlSb rods by micro-pulling down method

Description: We designed and supplied special crucibles for AlSb material. Thermal insulation and limitation of Sb losses were our first work. The protection of the growth environment was also one of our priority to avoid any pollution of the Fibercryst {mu}PD facility. When this work was achieved, the next step was the calibration of the heating power for these new crucibles. Then, it was the definition of single crystal growth conditions that oriented our research. Following our proposal, many growths att… more
Date: May 14, 2009
Creator: Bourret-Courchesne, Edith & Perrodin, Didier
Partner: UNT Libraries Government Documents Department
open access

Nanoporous films for epitaxial growth of single crystal semiconductor materials : final LDRD report.

Description: This senior council Tier 1 LDRD was focused on exploring the use of porous growth masks as a method for defect reduction during heteroepitaxial crystal growth. Initially our goal was to investigate porous silica as a growth mask, however, we expanded the scope of the research to include several other porous growth masks on various size scales, including mesoporous carbon, photolithographically patterned SU-8 and carbonized SU-8 structures. Use of photolithographically defined growth templates r… more
Date: October 1, 2007
Creator: Rowen, Adam M.; Koleske, Daniel David; Fan, Hongyou; Brinker, C. Jeffrey; Burckel, David Bruce; Williams, John Dalton et al.
Partner: UNT Libraries Government Documents Department
open access

Acquisition of Single Crystal Growth and Characterization Equipment

Description: Final Report for DOE Grant No. DE-FG02-04ER46178 'Acquisition of Single Crystal Growth and Characterization Equipment'. There is growing concern in the condensed matter community that the need for quality crystal growth and materials preparation laboratories is not being met in the United States. It has been suggested that there are too many researchers performing measurements on too few materials. As a result, many user facilities are not being used optimally. The number of proficient crystal … more
Date: December 9, 2008
Creator: Maple, M. Brian & Zocco, Diego A.
Partner: UNT Libraries Government Documents Department
open access

Float zone silicon sheet growth. Final report, September 23, 1993--December 31, 1996

Description: Energy Materials Research was organized in 1984. The specific objective of the company is to generate new concepts and to move targeted applications of newly developing technologies into commercial production. The initial technology described here is the outgrowth of a research program to develop concepts and techniques for low-cost energy production from renewable energy resources. The first major project implements an innovative process for the direct production of crystalline silicon sheet f… more
Date: April 1, 1997
Creator: Bleil, C.E.
Partner: UNT Libraries Government Documents Department
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Growth morphology of vicinal hillocks on the (101) face of KH{sub 2}PO{sub 4}: Evidence of surface diffusion

Description: The growth morphologies of vicinal hillocks on KH{sub 2}PO{sub 4} (101) surfaces have been investigated using atomic force microscopy. Both 2D and spiral dislocation growth hillocks are observed on the same crystal surface at supersaturations of {approximately}5%. Growth occurs on monomolecular 5 {Angstrom} steps both by step-flow and through layer-by-layer growth. The distribution of islands on the terraces demonstrate that surface diffusion is an important factor during growth. Terraces that … more
Date: January 10, 1995
Creator: Land, T. A.; De Yoreo, J. J.; Lee, J. D. & Ferguson, J. R.
Partner: UNT Libraries Government Documents Department
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Fabrication of large-volume, low-cost ceramic lanthanum halide scintillators for gamma ray detection : final report for DHS/DNDO/TRDD project TA-01-SL01.

Description: This project uses advanced ceramic processes to fabricate large, optical-quality, polycrystalline lanthanum halide scintillators to replace small single crystals produced by the conventional Bridgman growth method. The new approach not only removes the size constraint imposed by the growth method, but also offers the potential advantages of both reducing manufacturing cost and increasing production rate. The project goal is to fabricate dense lanthanum halide ceramics with a preferred crystal o… more
Date: October 1, 2008
Creator: Boyle, Timothy J.; Ottley, Leigh Anna M.; Yang, Pin; Chen, Ching-Fong; Sanchez, Margaret R. & Bell, Nelson Simmons
Partner: UNT Libraries Government Documents Department
open access

Precipitation and Pattern Formation under Far-From-Equilibrium Conditions

Description: Precipitates of a series of alkaline earth metal (barium and strontium) carbonates, chromates, phosphates, and sulfates were formed at high supersaturation by diffusion through silica hydrogel, agarose hydrogel, and the freshly developed agarosesilica mixed gels. The reaction vessels could be a small test tube, a recently designed standard micro slide cassette and a enlarged supercassette. Homogeneous nucleation is thought to have taken place, and particle development led to the formation of an… more
Date: August 1995
Creator: Chen, Peng, 1960-
Partner: UNT Libraries
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Simulating Interface Growth and Defect Generation in CZT – Simulation State of the Art and Known Gaps

Description: This one-year, study topic project will survey and investigate the known state-of-the-art of modeling and simulation methods suitable for performing fine-scale, fully 3-D modeling, of the growth of CZT crystals at the melt-solid interface, and correlating physical growth and post-growth conditions with generation and incorporation of defects into the solid CZT crystal. In the course of this study, this project will also identify the critical gaps in our knowledge of modeling and simulation tech… more
Date: November 1, 2012
Creator: Henager, Charles H.; Gao, Fei; Hu, Shenyang Y.; Lin, Guang; Bylaska, Eric J. & Zabaras, Nicholas
Partner: UNT Libraries Government Documents Department
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Development of advanced Czochralski growth process to produce low-cost 150-kg silicon ingots from a single crucible for technology readiness. First quarterly progress report, October 1, 1980-December 31, 1980

Description: Design, release for manufacture, and procurement of a modified CG2000 RC crystal grower proceeded. The construction, installation, and test of this machine is expected by March 1, 1981. The process development work will begin when the grower is completed. All of the hot zones, polycrystalline silicon, crucibles, dopant, seeds, and other supplies were quoted and purchase orders issued. Several exhaust gas analysis system equipment specifications and quotations were received and are under study. … more
Date: January 1, 1980
Partner: UNT Libraries Government Documents Department
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Ultrafast growth of wadsleyite in shock-produced melts and its implications for early solar system impact processes

Description: We observed micrometer-sized grains of wadsleyite, a high-pressure phase of (Mg,Fe)2SiO4, in the recovery products of a shock experiment. We infer these grains crystallized from shock-generated melt over a time interval of <1 fs, the maximum time over which our experiment reached and sustained pressure sufficient to stabilize this phase. This rapid crystal growth rate (=1 m/s) suggests that, contrary to the conclusions of previous studies of the occurrence of high-pressure phases in shock-me… more
Date: December 1, 2009
Creator: Tschauner, Oliver; Asimow, Paul; Kostandova, Natalia; Ahrens, Thomas; Ma, Chi; Sinogeikin, Stanislav et al.
Partner: UNT Libraries Government Documents Department
open access

Growth of large KDP crystals in the form of plates

Description: This paper suggests a new technique of growth-oriented KDP crystals in the form of plates. The technique includes: using small oriented seeds spaced between two parallel platforms with a rapid growth of crystals between these two platforms, in a tank containing a KDP solution. As a result, crystals in the form of plates can be obtained. The thickness of the crystal plate depends on the distance between platforms. The horizontal dimensions of the plate depend on the volume of solution and the di… more
Date: May 1, 1998
Creator: Beriot, E. & Tatartchenko, V.
Partner: UNT Libraries Government Documents Department
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Why in situ, real-time characterization of thin film growth processes?

Description: Since thin-film growth occurs at the surface, the analytical methods should be highly surface-specific. although subsurface diffusion and chemical processes also affect film properties. Sampling depth and ambient-gas is compatibility are key factors which must be considered when choosing in situ probes of thin-film growth phenomena. In most cases, the sampling depth depends on the mean range of the exit species (ion, photon, or electron) in the sample. The techniques that are discussed in this … more
Date: August 1, 1995
Creator: Auciello, O. & Krauss, A. R.
Partner: UNT Libraries Government Documents Department
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Growth phenomena in the surface layer and step generation from the edges of faceted crystals

Description: The mechanism of growth step generation from the edges of faceted crystals obtained from experimental results with KDP crystals is described. It shows that growth from the crystal edges is initiated by the deviation of the edges from their crystallographic orientation and formation of incomplete shapes of singular facets. The conditions for formation of the incomplete faceted shapes during dislocation growth are considered. It is shown that the process of step generation from the edges is deter… more
Date: July 29, 1999
Creator: Carman, L.; Smolsky, I. & Zaitseva, N. P.
Partner: UNT Libraries Government Documents Department
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Crystal growth and roughening of solid D{sub 2}

Description: Near the triple point, growth shapes of vapor deposited hexagonal close packed D{sub 2} crystals reveal two crystal orientations contain facets which persist up to the melt. This observation is in contrast with previous experiments on rare gas solids and H{sub 2} where the highest T{sub r} measured is 0.8 T{sub tp}.
Date: March 26, 1997
Creator: Kozioziemski, B.J.; Collins, G.W. & Bernat, T.P.
Partner: UNT Libraries Government Documents Department
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